The present invention relates to a system for collecting products dumped on the surface of a mass of water, and more specifically to a system for collecting petroleum products drifting on the sea due to discharge from submarine beds, collision of tankers, stranded tankers, or any other of the reasons and circumstances which give rise to the appearance of the dreaded "black tide".
Generally, the system of the invention involves positioning prismatic shaped cages at the sides of a tanker. The height of each one of these prismatic cages should be such that when the tanker is at ballast, the lower part of the cage will be submerged in the water, while the upper part will be above the maximum loading line of the tanker. The cages are secured to the beam-end of the tanker by attachment devices in the form of freely articulated connection points, so that the cages can be oriented in the most convenient direction with respect to the longitudinal axis of the tanker.
In the interior or each cage will be housed a series of floating suction pump inlet members or housings, also prismatic in shape, the dimensions of which should permit a high sensitivity to the least fluctuating movements of the liquid surface. In other words, if a floating pump inlet member has dimensions of 2 meters.times.0.4 meters.times.0.1 meter, then one of its faces having the measurements of 2 meters.times.0.1 meter should be oriented in the direction of travel of the tanker. The complete length of of this face is provided with an opening, the height of which is such that the lower edge of the opening will be situated below the floating line or the suction pump inlet members, at a depth equal to 0.01 meters.
This opening communicates with a funnel-shaped inner cavity of the floating pump inlet member, a smaller-dimensioned zone of which communicates with the outside through a hose which protrudes from the bottom of the floating pump inlet member.
Due to this arrangement, a mass of water entering the submerged part of the opening of the floating pump inlet member is passed through the hose, while the petroleum products drifting on the liquid surface are simultaneously absorbed.
The pump inlet members of the assembly are joined to each other by flexible couplings which permit, in spite of forming a type of barrier in a direction which could be perpendicular to that of travel of the tanker, each floating pump inlet member to independently adopt the buoyancy which corresponds thereto, depending on the surface of the sea. This ensures that the assembly of floating pump inlet members will always adapt to the form of the superficial profile of the water.
The end floating pump inlet members are joined to the cage through flexible couplings. This takes place so that fastening of the pump inlet members to the cage does not prevent the vertical displacement of the pump inlet members.
To prevent the pressure of the water during travel of the tanker from causing the assembly of suction pump inlet members to turn about the longitudinal axis thereof, which if it occurred would give rise to the positional change of the openings to an incorrect position, the pump inlet members are provided with horizontal guides situated at the lower and upper ends and at the front and rear zones thereof. These guides will be separated from the inner walls of the cages by approximately 0.01 meters, which permits complete freedom of vertical movement of the pump inlet members in the interior of the cages, while preventing the pump inlet members from turning about their longitudinal axes.
All the floating pump inlet members are provided with check valves to permit, when necessary, the hoses to be primed for a correct and perfect flow.
Obviously, when the tanks of the ship are being filled by a mixture of water and petroleum products from the pump inlet members, the draft of the ship will be increased and therefore the cages will be further submerged. This requires that the relative position of the pump inlet members with respect to the cages must be varied. This is achieved, since the pump inlet members, being floats, will rise in the interior of the cages.
In practice, the floating line of the pump inlet members will vary slightly. Since the suction hoses hang from the bottoms of the pump inlet members, the length of each hose will vary depending on the position of the respective pump inlet member in the interior of the cage. For this reason, when the pump inlet members are in the upper portions of the cages, they will support a greater weight of the hoses and, the floating lines will be raised with respect to the cages but lowered with respect to the water surface, and the inlet openings will be further submerged. Consequently, a greater amount of water than that necessary will enter, in which case the performance of the assembly will be reduced. Thus, if the amount of inlet water is to be maintained substantially constant, it is desirable to install a float cut-off valve for each opening of each pump inlet member. This ensures a constant inlet of water controlled by each pump inlet member, completely independent of the other pump inlet members.
The suction hoses of each of the floating pump inlet members descend to the lower part of the cages and are supported at the outer rear portions thereof to project upwardly to the ship where they will be connected to vacuum sources, e.g. suction pumps, if the tanker is provided therewith.
If the tanker is only provided with discharge pumps, to the loading line can be connected the hoses of the floats, by means of which a siphon action can be achieved once the hoses have been primed, whereby the lower tanks of the ship are filled and therefrom, by means of the discharge pumps, the remaining tanks are filled.